How to keep her cool?

Ken,
Thanks for the part number!
Below is what it said it fit in the listing so I thought I was good to go, but I guess not. After seeing the list I figured the odds were in my favor.

Ken,
The information in the specs pdf for the Hayden 2828 don’t list the bolt circle diameter. Happen to know....just don’t want to purchase another item I can’t use.
Thanks a bunch

I don't know the bolt circle diameter. But I have a 1982 GMC K2500 with a 6.2. It came with this same 7 blade fan. The 2828 Is the fan clutch I used to replace the bad one I had.
It is a 6 bolt fan with 7 blades Like the one you pictured. Looking on the Hayden site I see severe duty 216002 listed on page 25. This listing is also for the 82 with a 6.2 and 6 bolt clutch.

Part Number 216002 D STD 7.40 .75 .65 3.18 1.50 6.00BC 5.00MOUNT DIA 3.82 5/16-18 HOLE (6) The 215052 Is for a 6.2 with 4 bolt fan. The mounting hub specs are the same. I found this on the Hayden Site. Hope this helps.

Ken, thank you for the added info that really helped my piece of mind.
i found one on fleeBay on close out for $44.99. I’m going to take a chance on that one.
i really appreciate the assistance.

Glad I could help, This is what SS is all about. Sometimes the answer just isn't in the TM.

Ken,
I decided to use a micrometer and a drillpress and drill the new holes offset. Used a 1/2 socket which the OD was just a papers width under the hole for the centering stud on the pump pulley. Made a template and went at it. Came out perfect and couldn’t have fit better. Pic below.
Now for the crappy part. My Performance Radiator 3 row HE is perfect in every way save one......the oil line ports are threaded for 3/4-16 and my oil lines are 3/4-18. The trans lines are correct at 18 pitch. Wasted my entire Father’s Day afternoon thinking I was an idiot and can’t thread oil lines....ugh.
I’ll go take it in tomorrow and see what they say. May have to have the old unit reworked by them and just run what I brung.

Anyone else have this issue?
thanks

Man I hate to hear that. I wonder is a pass with a bottoming tap would fix your problem? Or do you have a industrial supply around that carries HYD fittings? Maybe you could adapt the lines to the ports. But good job on the clutch mod. Somebody has heard of "adapt and overcome before."

'

Thank you on the clutch mod. Turns out the rad shop said GM changed their thread pitches that year.....gave some adapters but he gave 18 pitch male side and 18 on the female.....getting closer. I’ll take the new rad and oil lines into their shop tomorrow and get it resolved once and for all. The old timer at the rad shop said the adapters should have shipped with the rad but UPS was less that delicate with shipping. So much so that the rad shop finished the unintended unboxing to ensure it wasn’t damaged.,...just missed that the fittings were missing.

Update:
I talked to Performance Radiator again and we’ve elected to take my old rad and remove and clean the passenger side take were the oil lines connect and put it onto the new HE rad. Then I know my oil lines will fit and I’ll get the benefit of a mostly new rad.

On the subject of cooling. I have had more then 1 CUCV that was an issue with heating up. One for sure had bad heads that were cracked. The cracks were not allowing the oil and coolant mixture but were allowing heat build up. Of course the resolution was another set of heads and new head gaskets. As I said in the past. Change the head gaskets if you are having a cooling problem. Every little bit helps. Also take notice when you have it floored going up a steep grade and it just seems to hang there. Not gaining or loosing speed. Let off the fuel a bit and it will stay about the same. All the fuel is doing is making heat and it doesn't make a difference in speed any way. More fuel more heat. These things run hot on hard pulls and under massive load as hill climbs. You can add more fans and cross overs the heat is being generated by the fuel and work of the engine and transmission. My Son blew an engine and transmission in 5 miles on I 78. The transmission started slipping then the engine over heated and that was it both left loose. Good Luck. But sometimes things are not as easy as a new radiator and fan. NOT saying this is the case. But be aware.

Last posting two and a half years ago on this topic.
Sorry for my late arrival/read-up...

Curious to hear if any results from bypass system by now have been evaluated and feed back can be given?
Not that I have overheating issues, as I am not even driving my M1009 yet but still rebuilding... and hoping for fun by next year late summer...

Any expert views on this here certainly appreciated: https://www.thedieselpageforums.com/tdpforum/showthread.php?25230-Bypass-cooling-for-the-6-2-6-5
I am reasonably mechanically inclined and this reads plausible and logic: cooling fluid from waterpump flows through the lower block and alongside the cylinder walls all the way to the back, collecting heat from cylinder walls and lower engine block and at the very end of the block half the cooling fluid then flows up and into the cylinder heads, with the other half flowing up through 4 intermediate ports and flows back to the front of the cylinder heads and from there to the thermostat and radiator.
Interested in reading SME comments?

Thanks,
Jake

Jake59 said:

Last posting two and a half years ago on this topic.
Sorry for my late arrival/read-up...

Curious to hear if any results from bypass system by now have been evaluated and feed back can be given?
Not that I have overheating issues, as I am not even driving my M1009 yet but still rebuilding... and hoping for fun by next year late summer...

Any expert views on this here certainly appreciated: https://www.thedieselpageforums.com/tdpforum/showthread.php?25230-Bypass-cooling-for-the-6-2-6-5
I am reasonably mechanically inclined and this reads plausible and logic: cooling fluid from waterpump flows through the lower block and alongside the cylinder walls all the way to the back, collecting heat from cylinder walls and lower engine block and at the very end of the block half the cooling fluid then flows up and into the cylinder heads, with the other half flowing up through 4 intermediate ports and flows back to the front of the cylinder heads and from there to the thermostat and radiator.
Interested in reading SME comments?

Thanks,
Jake

Click to expand...

OK, at the risk of getting flamed, I will jump in here with my opinion. I agree with everything Jim said in his 2006 post on the DieselPage. The bypass system currently commercially offered by Paradox does exactly what is is advertised to do - re-route some of the coolant from the rear of the heads back to the front of the engine via -AN hose, thereby BYPASSING the heads. However that is the problem. The coolant NEEDS to circulate through the heads in order to pick up the heat and return it to the radiator.

Jim summed it up in his post -
In conclusion: Taking coolant out at the back of the heads reduces the amount of coolant flowing forward and through the heads - plain and simple. That cannot be argued. The cylinder heads generate most of the heat in a running engine, and the cooling system has to move enough coolant through them to prevent damage. If a bypass cooling strategy is used, you may see a lower engine coolant temperature, which is what you'd expect if the coolant isn't picking up as much heat as it should in the cylinder heads. Not removing heat from the cylinder heads could result in hot spots that develop in the area around the exhaust valves and exhaust runners, which won’t be reflected by the engine temperature sensor. I’m open to third party data and test results, but till then my opinion is that bypass cooling may actually contribute to cylinder head cracking - engine damage...

This is all I will say on the subject. I fully expect the Paradox guy to jump in and flame me and everyone else who disagrees with his therory that his "bypass" system actually improves engine cooling.

Hope this helps.

Something I am trying on my 6.2 motor is the 96 single thermostat cross over with the restricting thermostat. It does the same thing as the restricted fitting that is sold. Temperature testing will be coming soon on my motor stand.

This is definitely an interesting topic. I have a Paradox system on my M1008, unfortunately I do not have any scientific or documented data on the before and after results. My opinion is that the 6.2 is known for cracked heads etc, taking any steps to help prevent this from happening is worth a try. My 6.2's may destroy heads with or without the Paradox system.

On the topic about "Flaming" another member, we do not need any drama with this type of behavior. As long as we keep this discussion civil, this can be a very interesting and useful thread. Opinions are OK, scientific data and actual test results are welcome, derogatory remarks or outright bashing will not be tolerated. It's OK to disagree with another persons opinion provided that it is done in a respectable way. We have a good clean thread, let's keep it that way.

antennaclimber said:

This is definitely an interesting topic. I have a Paradox system on my M1008, unfortunately I do not have any scientific or documented data on the before and after results. My opinion is that the 6.2 is known for cracked heads etc, taking any steps to help prevent this from happening is worth a try. My 6.2's may destroy heads with or without the Paradox system.

On the topic about "Flaming" another member, we do not need any drama with this type of behavior. As long as we keep this discussion civil, this can be a very interesting and useful thread. Opinions are OK, scientific data and actual test results are welcome, derogatory remarks or outright bashing will not be tolerated. It's OK to disagree with another persons opinion provided that it is done in a respectable way. We have a good clean thread, let's keep it that way.

Click to expand...

Thanks. I was hoping for a shield.

As you all know I have driven and used the CUCV's for just about everything. I used them hard. I would find it hard to defend an add on kit either way. I have had hundreds of thousands of miles on the 6.2 engines. Most issues I had I went looking for. The head gaskets and heads are no different then any other vehicle of the same vintage. 350 Chevy heads were always a sought after thing. They were also susceptible to cracks and warpage. I sold everyone I ever had and spent a lot of money getting them checked before I sold them just to find out they were cracked. The 6.2 is in the same boat. I have 8 heads that are questionable. One guy says they are fine and the other says they are not. I have a brand new set of GM 6.2 heads in wooden crates I will probably use for book ends some day. I bought them 20 years ago and decided to just keep using used(Heads) parts as long as I had them. New heads have a thousand year shelf life where used parts get in my way and when scrap goes up and they get me in the way again they get scrapped. I can see no advantage to adding an extra kit when the CUCV's I have had have lasted 200K plus. That is pending a clean , leak free, free flowing radiator and keeping the coolant clean , and cooling system maintained. I would stick with the stock system and KISS. (Keep It Simple Stupid). That is just my opinion. I can't make a silk purse out of a sows ear. The CUCV will always be a simple CUCV no matter what you add to it. That is why I like and enjoy them so much. Take Care and Be Safe.

KamikazeKunze said:

Same here. 29k clean as whistle.

So....after all this how do guys even move these CUCV’s with lifts and 37” hummer wheels?
I would think you have to have 12v Cummins swap and a 4L80E

Click to expand...

Mine moves slowly.

Sharecropper said:

OK, at the risk of getting flamed, I will jump in here with my opinion. I agree with everything Jim said in his 2006 post on the DieselPage. The bypass system currently commercially offered by Paradox does exactly what is is advertised to do - re-route some of the coolant from the rear of the heads back to the front of the engine via -AN hose, thereby BYPASSING the heads. However that is the problem. The coolant NEEDS to circulate through the heads in order to pick up the heat and return it to the radiator.

Jim summed it up in his post -
In conclusion: Taking coolant out at the back of the heads reduces the amount of coolant flowing forward and through the heads - plain and simple. That cannot be argued. The cylinder heads generate most of the heat in a running engine, and the cooling system has to move enough coolant through them to prevent damage. If a bypass cooling strategy is used, you may see a lower engine coolant temperature, which is what you'd expect if the coolant isn't picking up as much heat as it should in the cylinder heads. Not removing heat from the cylinder heads could result in hot spots that develop in the area around the exhaust valves and exhaust runners, which won’t be reflected by the engine temperature sensor. I’m open to third party data and test results, but till then my opinion is that bypass cooling may actually contribute to cylinder head cracking - engine damage...

This is all I will say on the subject. I fully expect the Paradox guy to jump in and flame me and everyone else who disagrees with his therory that his "bypass" system actually improves engine cooling.

Hope this helps.

Click to expand...

Coolant flows up and out of the heads at the front. The rear of the block has little flow compared to the front. By drawing coolant at the back you create flow where there was little before. We do not claim our kit reduces system temperature at all, however it does balance the temps front to back by creating a flow path for the overheated rear of the block. Please read our blog on the subject so you can better understand how the coolant flows in these engines. https://paradoxbydesign.com/blogs/news/the-humvee-diesel-engine-cooling-paradox

I know that the science is not always easy to follow so here is another way to look at this.

GM and later GEP continuously worked on this rear engine overheating issue over the life of the 6.2 and 6.5 engines. First they changed the crossover design, then they added a dual thermostat housing, then a higher flow pump, in HMMWVs they went to a geared fan, then when all else failed to solve the issue they did one of the worst admissions of failure in recent memory. They oversized the bores of just cylinders #7&8 so that when they overheated they would not score the cylinder walls, break rings and seize up the engine! If you don't believe the science, believe the trail of evidence!

Later, GM in the development of the LS engines knew that they needed precise balance of the cylinder to cylinder temps so they could run lean enough to meet the stricter emissions laws and not cause detonation. They were able to get away with rear engine over temps in earlier gas engines by simply running richer but with added emissions standards could no longer do this. GM came up with what they call the Steam Vent. The Steam Vent is a coolant pipe which draws coolant from the back of the block and reintroduces it at the front to create better flow to the back of the block/heads. This is the same as we are doing with our kits.